Field of the Invention
The present invention relates to wireless communications, and more specifically, to a cell reselection method based on an MBMS (Multicast Broadcast Multimedia Service) in a wireless communication system and an apparatus supporting the same.
Related Art
3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution), an advancement version of UMTS (Universal Mobile Telecommunications System), is introduced in 3GPP release 8. 3GPP LTE adopts OFDMA (orthogonal frequency division multiple access) for downlink and SC-FDMA (Single Carrier-frequency division multiple access) for uplink. It adopts MIMO (multiple input multiple output) having up to four antennas. Recently, 3GPP LTE-A (LTE-Advanced), the evolution of 3GPP LTE, is in discussion.
A terminal represented by the mobile device may be on the move, and thus, a deterioration of the quality of service being presently provided or a cell providing a better service may be discovered. Accordingly, the terminal may shift to the new cell.
In order for the terminal to shift to the new cell, the terminal steadily performs measurement on the serving cell and neighbor cells. In case the result of measurement shows that conditions for making the shift are met, the terminal may receive an instruction from the serving cell or may directly move.
The terminal may receive a further enhanced service by maintaining the link to the cell offering a particular service or a cell permitted to access. As an example, it may be preferable that a terminal desiring to receive the MBMS (Multicast Broadcast Multimedia Service) may approach the cell providing the MBMS as possible to receive the service. As a method for the purpose, a separate priority may apply to the frequency of the cell providing the MBMS, so that the terminal may reselect the cell providing the MBMS as possible.
A terminal receiving the MBMS or desiring to receive the MBMS, in case departing from the cell coverage in which the MBMS is provided, may perform cell reselection by applying the higher priority to the frequency at which the MBMS is predicted to be provided. The target cell selected through such cell reselection may be a cell that does not actually provide the MBMS, and the terminal approaching such cell may be against the original purpose of performing cell reselection by adjusting the priority.